All-wheel distributor gearbox for a motor vehicle

ABSTRACT

An all-wheel distributor transmission ( 1 ) is described for a motor vehicle comprising a planetary gear set as multiplication step ( 2 ) for a switchable off-road gear and a planetary gear set ( 3 ) with variable division for distributing a drive torque onto a front axle and a rear axle. The all-wheel distributor transmission ( 1 ) also has an adjustable lock ( 4 ) for locking between the front axle and the rear axle, the lock ( 4 ) and the multiplication step ( 2 ) being actuatable via a controllable drive device ( 5 ). The drive device ( 5 ) comprises a drive shaft ( 6 ) and two output shafts ( 7, 8 ), the first output shaft ( 7 ) being in operative connection with the multiplication step ( 2 ) and the second output shaft ( 8 ) being in operative connection with the lock ( 4 ). A torque introduced via the drive shaft ( 6 ) can be applied on the first or the second output shaft ( 7  or  8 ) according to a control of a shift unit ( 10 ) for actuating the lock ( 4 ) or the multiplication step ( 2 ).

FIELD OF THE INVENTION

[0001] The invention relates to an all-wheel distributor transmission ofa motor vehicle of the kind specified in the preamble of claim 1.

BACKGROUND OF THE INVENTION

[0002] In U.S. Pat. No. 6,022,289 has been described an all wheeldistributor transmission of a motor vehicle in which an off-roadgearshift and a lock are actuated via a common drive device. The lockdesigned here as multi-disc lock is brought by an actuator of the drivedevice via a lever arm from an open position to a closed position and atthe same time to a position that locks a front-wheel input with arear-wheel input. The off-road gearshift is actuated via a cam discwhich converts a rotatory input originating from the actuator to atranslatory movement or actuation of the off-road gearshift.

[0003] According to the invention this problem is solved with a devicein conformity with the features of claim 1.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Other advantages and advantageous developments of the inventionresult from the sub-claims and the embodiment fundamentally describedwith the aid of the drawing which shows The invention will now bedescribed, by way of example, with reference to the accompanyingdrawings in which:

DETAILED DESCRIPTION OF THE INVENTION

[0005] The invention relates to an all-wheel distributor transmission ofa motor vehicle of the kind specified in the preamble of claim 1.

[0006] In all-wheel distribution transmissions for motor vehicles knownfrom the practice, a planetary gear set as multiplication step for aswitchable off-road gear and an adjustable block for locking between afront axle and a rear axle of the motor vehicle are respectivelyactuated independently of each other via two separate actuators orelectromotors.

[0007] However, those all-wheel distributor transmissions with devicesfor actuating an off-road gearshift and an adjustable lock have thedisadvantage of needing a large installation space and working inopposition to the general requirement in motor vehicle technology of aweight reduction to minimize the fuel consumption.

[0008] In U.S. Pat. No. 6,022,289 has been described an all-wheeldistributor transmission of a motor vehicle in which an off-roadgearshift and a lock are actuated via a common drive device. The lockdesigned here as multi-disc lock is brought by an actuator of the drivedevice via a lever arm from an open position to a closed position and atthe same time to a position that locks a front-wheel input with arear-wheel input. The off-road gearshift is actuated via a cam discwhich converts a rotatory input originating from the actuator to atranslatory movement or actuation of the off-road gearshift.

[0009] The lock is opened and closed and the off-road gear is engaged ordisengaged via the respective direction of rotation of the actuator andof the electromotor corresponding therewith. This means, for example,that a clockwise rotation of the electromotor produces an adjustment ofthe off-road gear in a shifting position or an adjustment of themulti-disc lock in a closing position. The disengagement of the off-roadgear or a locking of the multi-disc lock is produced, for example, by acounterclockwise rotation of the electromotor.

[0010] It is here disadvantageous, however, that the differentdirections of rotation of the electromotor needed for actuation of themulti-disc lock and of the off-road gearshift over their respectiveoverall range of operation cause during the reversal of direction ofrotation, a so-called upset play which, specifically in the control ofthe input for the multi-disc lock, makes only unsatisfactorily possiblean exact adjustment of an applied pressure.

[0011] It is also disadvantageous that the compression of the discsduring the closing or in closed position of the multi-disc lock due to abending of the lever cannot be exactly defined, since while the discsare compressed, the driving energy of the actuator applied to themulti-disc clutch is partly consumed as lost energy by the deformationof the lever and an exact relationship no longer exists between thecompression and the rotation angle of the actuator and the drive shaftthereof respectively.

[0012] The problem on which this invention is based is, therefore, tomake available an all-wheel distributor transmission for a motor vehiclewhich needs small installation space and with which can be carried outan exact actuation of an off-road gearshift and of a lock of theall-wheel distributor transmission.

[0013] According to the invention this problem is solved with a devicein conformity with the features of claim 1.

[0014] With the inventive all-wheel distributor transmission theconstructional expenses and the number of parts are advantageouslyreduced, since the actuation of the lock and of the off-road gearshiftis implemented via a single drive device. The possible compact andlow-wear design economizes both installation space and weight and alsocosts by the reduction of the required parts.

[0015] By the fact that the lock and the clutch for the planetary gearset, which serves as multiplication step for the switchable off-roadgear, can be actuated via a common drive device and a torque of thedrive shaft of the drive device is applied upon the first drive shaft orthe second drive shaft of the drive device depending respectively on acontrol of the switching device for actuation of the lock or of themultiplication step, the expense for control and regulation of thealternative actuation of the lock and of the off-road gearshift isconsiderably reduced. This advantage results from the fact that thereare controlled only one machine such as an electromotor of the drivedevice that produces the drive torque and only one switching device forrerouting the drive torque from the drive shaft to one of the two driveshafts.

[0016] Other advantages and advantageous developments of the inventionresult from the sub-claims and the embodiment fundamentally describedwith the aid of the drawing which shows:

[0017]FIG. 1 is a schematic representation of an inventive all-wheeldistributor transmission of a motor vehicle with an off-road gearshiftand a multi-disc lock;

[0018]FIG. 2 is a simplified representation of a drive device of theall-wheel distributor transmission according to FIG. 1 which is inoperative connection with a linear drive for the off-road gearshift;

[0019]FIG. 3 is a half section through the drive device according toFIG. 1 and FIG. 2 with an electromagnetic clutch and an electromagneticbrake in detached representation; and

[0020]FIG. 4 is an extensively schematized representation of the controlrange of the drive device.

[0021] Referring to FIG. 1, it shows a schematic representation of anall-wheel distributor transmission 1 for a motor vehicle with a firstplanetary gear set as multiplication step 2 for a switchable off-roadgear and a second planetary gear set 3 with variable division fordistribution of a drive torque onto a front axle and a rear axle. Theall-wheel distributor transmission 1 further comprises an adjustablelock 4 for locking between a front-axle output line and a rear-wheeloutput line, the lock 4 and the multiplication step 2 being actuatablevia a controllable drive device 5.

[0022] The drive device 5 comprises one drive shaft 6 and two outputshafts 7, 8, the first output shaft 7 being in operative connection withthe multiplication step 2 and the second output shaft 8 in operativeconnection with the lock 4. The drive shaft 6 constitutes at the sametime an output shaft of an electromotor 9 of the drive device 5 andtransmits during operation of the electromotor 9 a torque which,depending on a control of a shift unit 10 of the drive device 5 foractuating the lock 4 or the multiplication step 2, can be brought fromthe drive shaft 6 to the first output shaft 7 or the second output shaft8.

[0023] In the area of its end remote from the drive shaft 6, the firstoutput shaft 7 is in operative connection with a linear drive 11 whichhas a ball-threaded pinion 12 and a tiltable drive 13. The ball-threadedpinion 12 comprises a ball nut 15 having several balls 14 which engagesin a spindle-like area of the first output shaft 7 and upon a rotationof the first output shaft 7 is adjusted in the axial direction thereofand produces a tilting motion of the driver 13. In the design shown, theball nut 15, during a counterclockwise rotation of the electromotor 9,is displaced in axial direction of the first output shaft 7 toward adrive device 5 and during a clockwise rotation of the electromotor 9 isadjusted in an opposite direction.

[0024] The driver 13 is tiltably mounted in a housing 16 of theall-wheel distributor transmission 1 and connected with a synchronizerunit 17 of the multiplication step 2, a tilting motion of the driver 13producing a translatory movement of the gear change sleeve of thesynchronizer unit 17.

[0025] It is understood that in an alternative embodiment the expert canalso provide instead of the driver 13 shown here a non-tiltable forkrigidly connected with the linear drive.

[0026] In its end remote from the drive shaft 6, the second output shaft9 is in operative connection with the lock 4 via a multiplication device18, said multiplication device 18 being firmly connected with a shaft 19and having in the housing 16 rotatably disposed gear wheels 20, 21. Thefirst gear wheel 29 of the shaft 19 engages with a spur wheel 22 firmlyconnected with the second output shaft 8.

[0027] The lock 4 as a set wheel 23 which is provided with a spline 24that partly extends over the periphery of the set wheel 23 and isengaged with the second gear wheel 21 of the shaft 19.

[0028] The lock 4 further comprises several axially movable discs, theinner discs 25 of the lock 4 being non-rotatably connected with arear-wheel output shaft 28 of the all-wheel distributor transmission 1and outer discs 27 of the lock 4 being non-rotatably connected with afront-wheel output shaft 26 of the all-wheel distributor transmission 1.

[0029] Between the disc sets 25, 27 and the set wheel 23 there isprovided a disc-like adjusting element 29 axially movable and firmlydisposed in the housing 16 of the all-wheel distributor transmission 1and having on its side facing the set wheel 23 spiral shaped grooves 29Awhose depth steadily increases in the manner of a sloping path until amaximum depth point. The set wheel 23 in addition has upon its sidefacing the adjusting element 29 spiral-shaped recesses 23A correspondingwith the grooves 29A of the adjusting element 29, rolling bodies 61being passed between the set wheel 23 and the adjusting element 29 intothe grooves 29A and the recesses 23A.

[0030] The set wheel 23 forms with the adjusting element 29 and therolling bodies or balls 61 disposed therebetween a ball-ramp systemwherein the grooves 29A and the recesses 23A are mutually disposed sothat a rotation of the set wheel 23 produces a hobbing of the rollingbodies 61 in the grooves 29A and the recesses 23A, the same as an axialmovement of the adjusting element towards or away from the disc sets 25,27 when the set wheel 23 is axially stationary. The rotation of the setwheel 23 is produced by the transmission of the drive torque originatingfrom the drive device 5 to the set wheel 23 via the multiplicationdevice 18.

[0031] This construction, in which small flexible parts are used, ischaracterized by a very advantageous hysteresis behavior with smallhysteresis whereby a very precise adjustment of the multi-disc lock 5 ispossible.

[0032] The shift unit 10 of the drive device 5 comprises anelectromagnetic clutch 30 with which a power flow can be producedbetween the drive shaft 6 and the first output shaft 7 or the secondoutput shaft 8. To form the power flow, the electromagnetic clutch 30 isfurnished with an axially and rotatorily movable guided coupling element31 which is non-rotatably connected with the drive shaft 6, anddepending on a current supply of the electromagnetic clutch 30, producesthe power flow between the drive shaft 6 and the first output shaft 7 orthe second output shaft 8.

[0033] In the operation of the electromotor 9 and when theelectromagnetic clutch 30 is controlled to produce a power flow betweenthe drive shaft 6 and the first output shaft 7, there takes place anactuation of the off-road gearshift 2 via the linear drive 11 when theoff-road gear is not engaged during a counterclockwise rotation of theelectromotor in the sense that the ball-threaded pinion 12 is displacedin axial direction of the first output shaft 7, a tilting motion of thedrive 13 having as consequence a translatory movement of the gear changesleeve of the synchronizer unit 17. During clockwise rotation of theelectromotor 9, when power flow exists between the drive shaft 6 and thefirst output shaft 7, the gear change sleeve of the synchronizer unit 17is again adjusted via the linear drive 11 back to the neutral positionshown in FIG. 1.

[0034] On the other hand, if the electromagnetic clutch 30 is controlledso that a power flow exists between the drive shaft 6 and the secondoutput shaft 8, the drive torque of the electromotor 9 transmitted bythe drive shaft 6 to the second output shaft 8 produces a rotation ofthe set wheel 23 which, in turn, results in a translatory motion of theadjustment element 29 of the lock 4 to be closed in direction of thedisc sets 25, 27.

[0035] If the power flow between the drive shaft 6 and the second outputshaft 8 is cut off or the electromotor 9 shifts without current, aspring device (not shown in detail) of the lock 4 exerts a recoil forceupon the disc sets 25, 27 which, in turn, produces a translatory motionof the adjusting element 29 in direction of the set wheel 23 for openingthe lock 4.

[0036] By the fact that the multi-disc lock 4 is always brought from anopen to a closed or locking position by a direction of movement ordirection of rotation of the electromotor 9, only a small expenditure isneeded for adjustment.

[0037] When the front-wheel output shaft 26 and the rear-wheel outputshaft 28 are to be locked with each other, the lock 4 is closed via thedrive device 5 and subsequently held in locking position by theelectromotor 9 as long as required. When the locking cation of the lock4 is again to be cut off, either the power flow between the secondoutput shaft 8 and the drive shaft 6 is cut off via the electromagneticclutch 30 or the electromotor 9 shifts currentless, the spring device ofthe lock 4 acting as above described in axial direction of therear-wheel output shaft 28 upon the adjusting element 29. By virtue ofthe configuration of the grooves 29A of the adjusting element 29 and therecesses 29A of the set wheel 23 and the rolling bodies or balls 61situated therebetween, the set wheel 23 is reset in rotation and thelock 4 is opened.

[0038]FIG. 2 shows the drive device 5 with the linear drive 11 indetached position and must make clear the mode of operation of thelinear drive 11 and the tilting motion of the drive 13 as result of anaxial adjustment of the ball-threaded pinion 12. The driver 13 isnon-rotatably supported in the housing 16 on a rotation point 32 and onits end facing the first output shaft 7 is rotatably connected with theball-threaded pinion 12. On its end remote from the ball-threaded pinion12, the drive 13 is connected with the synchronizer unit 17 shown inFIG. 1 and during rotation around the rotation point 32 produces atranslatory movement of the sliding sleeve of the synchronizer unit 17.The end of the driver 13 remote from the ball-threaded pinion 12undergoes here, in axial direction of the first output shaft 7, adeflection which leads to the adjustment of the sliding sleeve of thesynchronizer unit 17 and an engagement or disengagement of the off-roadgear.

[0039]FIG. 3 shows the drive device 5 in detached position where thedrive shaft 6 is designed in the area of its end facing the outputshafts 7, 8 with a flange-like collar 34 on which a resilient element 35of the coupling element 31 designed here as leaf spring or diaphragmspring is non-rotatably fastened.

[0040] In the instant embodiment the flange-like collar 34 is designedintegrally with a hollow cylindrical part 36 firmly connected with thedrive shaft 6, the connection being provided between the hollowcylindrical part 36 and the drive shaft 6 in the area of the end of thehollow cylindrical part 36 remote from the output shafts 7,8 and thearea of the end of the drive shaft 6 facing the output shafts 7, 8. Thehollow cylindrical part 36 extends in axial direction of the drive shaft6 so that the first output shaft 7 engages in a central hole 37 of thehollow cylindrical part 36, an anti-friction bearing 39 being situatedbetween the first output shaft 7 and the hollow cylindrical part 36 forabsorbing the radial forces acting upon the flange-like collar 34 andthe hollow cylindrical part 36.

[0041] The arrangement and configuration of the hollow cylindrical part36 and of the anti-friction bearing 38 between the first output shaft 7and the hollow cylindrical part 36 ensures an exact positioning of theparts relative to each other and a compact construction of the drivedevice 5.

[0042] Examining the construction of the electromagnetic clutch 39, ithas an integral coil 39 which is located in an annular magnetic body 41of U-shaped cross section.

[0043] The coupling element 31 is made in addition to the resilientelement 35 with an annular guide element 42 of L-shaped cross sectionwhich is movably guided upon the magnetic body 41 of the electromagneticclutch 30 rotatorily and in axial direction of the drive shaft 6, theguidance of the guide element 42 upon the magnetic body 41 being devicedso that a rotation movement of the drive shaft 6 be transmitted to thehollow cylindrical part 36, the resilient element 10 and also to theguide element 42, and can be carried out by the latter.

[0044] On the guide element 42 is fastened an annular transmissionelement 43 of at least almost U-shaped cross section, the guide element42 and the transmission element 43 constituting the armature of theelectromagnetic clutch 30. When the electromagnetic clutch 30 issupplied with current, the guide element 42 an the transmission element43 are displaced in axial direction of the drive shaft 6 in direction ofboth output shafts 7, 8 along the guideways of the magnetic body 41against a retaining force generating by a reversible deformation of theresilient element 35.

[0045] The second output shaft 8 is designed as a hollow shaftsurrounding the first output shaft 7 and on its end facing the driveshaft 6 can be operatively connected with the coupling element 31 or agearing 44 of the transmission element 43 so as to obtain anon-rotatable connection between the drive shaft 6 and the second outputshaft 8 in currentless state of the electromagnetic clutch 30. Thegearing 44 of the transmission element 43 is designed as an innergearing extending over the whole periphery of the transmission element43 and engaging in a spline of the second output shaft 8 formed on oneend of the output shaft 8 which end faces the drive shaft 6 and expandsin the manner of a funnel.

[0046] It obviously is at the expert's discretion to provide, instead ofthe form-locking connection between the transmission element 43 and thesecond output shaft 8, a force-locking connection such as a frictionalconnection via two friction faces. Besides, the non-rotatable connectioncan also be made, instead of via the gearing described, via one othersuitable form-locking connection.

[0047] The first output shaft 7 is provided in the area of its endfacing the drive shaft 6 with a collar 45 with which, in thecurrent-supplied state of the electromagnetic clutch 30, contacts thecoupling element 31 or the transmission element 43 so that anon-rotatable connection exists between the drive shaft 6 and the firstoutput shaft 7 and the drive torque introduced via the drive shaft 6 istransmitted via the coupling element 31 to the first output shaft 7.

[0048] According to the design of FIG. 3, the collar 45 of the firstoutput shaft 7 is designed as a separate flange-like part connected withthe first output shaft 7 by a force fit. But the expert is allowedoptionally to design the collar 45 integral with the output shaft 7, thesame as to provide one other force-locking or form-locking connection—inany case non-rotatable—between the first output shaft 7 and the collar45.

[0049] In current-supplied state of the electromagnetic clutch 30, thecoupling element 31 or the guide element 42 and the transmission element43 are compressed in axial direction to the collar 45 by the electricfield produced by the integrated coil 39 of the electromagnetic clutch30, the gearing 44 of the transmission element 43 being disengaged fromthe spline of the second output shaft 8. Thus, in current-supplied stateof the electromagnetic clutch 30, the connection between the drive shaft6 and the second output shaft 8 is cut off and a frictional engagementis created between the transmission element 43 and the collar 45 so thata power flow exists between the drive shaft 6 and the first output shaft7 via the coupling element 31.

[0050] When the electromagnetic clutch 30 is not current-supplied, thetransmission element 43 and the guide element 42 are displaced in axialdirection of the drive shaft 6 from the collar 45 toward the coil 39 ofthe electromagnetic clutch 30 by the potential energy fed to theresilient element 35 when the electromagnetic clutch 30 is supplied withcurrent. Thereby is cut off the frictional connection between thetransmission element 43 and the collar 45 and the gearing 44 of thetransmission element 43 again is engaged with the spline of the secondoutput shaft 8.

[0051] In the area of the drive shaft, to discharge the drive device 5,an electromagnetic brake is provided with which the drive shaft,depending on a current supply of the electromagnetic brake 46, isnon-rotatably kept in one position. The electromagnetic brake 46 has anintegral coil 47, which coil 47 is situated in an annular magnetic body49 designed with U-shaped cross section.

[0052] The electromagnetic brake 46 further comprises a brake element 50non-rotatable with the drive shaft 6 and movable in axial direction ofthe drive shaft 6 which, in current-supplied state of theelectromagnetic brake 46, forms a power flow between the drive shaft andthe electromagnetic brake 46. When the electromagnetic brake 46 is notcurrent-supplied, the brake element 50 is located in axial direction ofthe drive shaft 6 spaced from the coil 47 and the magnet body 19 of theelectromagnetic brake 46. Due to the contact between the brake element50 and the magnet body 47 of the electromagnetic brake 46 and afastening of the magnet body 49 in a housing 51 of the drive device 5,the drive shaft 6 is kept via the electromagnetic brake 46 in a desiredstationary position with applied torque without a drive torque or acounter-torque having to be applied by the drive device 5.

[0053] The applied torque acts upon the drive shaft 6 depending on theposition of the electromagnetic clutch 30 of the first output shaft 7 orof the second output shaft 8 and of the multi-disc lock 4 or of themultiplication step 2. For the case that by the drive device 5 thereshould be applied a counter-torque that counteracts the torque appliedon both output shaft 7, 8 or on one output shaft 7 or 8, theelectromotor 9 of the drive device 5 could be permanently supplied withcurrent. But this is undesired, since the permanent current supply ofthe electromotor 9 needed to maintain the counter-torque requires a highinput of energy and would have the consequence of an undesired heatingof the drive unit 5. This is successfully prevented by using theelectromagnetic brake 46.

[0054] In order to cut off with certainty the frictional connectionbetween the brake element 50 and the magnet body 49 of theelectromagnetic brake 46 during transition from current-supplied tocurrentless state of the electromagnetic brake 46, there is providedbetween a shaft flange 52 of the drive shaft 6 and the brake element 49one other resilient element 53 which, as result of the axialdisplacement of the brake element 50 in the current-supplied state ofthe electromagnetic clutch 46, undergoes a reversible deformation andstores potential spring energy. During transition to a currentless stateof the electromagnetic brake 46, the stored energy leads to an axialdisplacement of the brake element 50 from the magnet body 49 of theelectromagnetic brake 46 back to an idle position of the brake element50. The shaft flange 52 is fixedly connected with the drive shaft 6 viaa press fit and kept in axial direction of the drive shaft 6 by therecess 54 of the drive shaft 6.

[0055] The electromagnetic clutch 30, the same as the electromagneticbrake 46, is fixedly and immovably situated by its fixture 41 in thehousing 51 of the drive device 5. With regard to their construction, theelectromagnetic clutch 30 and the electromagnetic brake 46 are basicallyof the same kind, the electromagnetic fields produced having differenteffects upon the parts that surround them. The field of theelectromagnetic clutch 30 thus produces an ejection of the couplingelement 31 whereas the field of the electromagnetic brake 46 produces anattraction of the brake element 50 which constitutes the armature of theelectromagnetic brake 46. The magnetic bodies 41, 49 are made of iron inorder to make possible optimally to build the electromagnetic field.

[0056] The drive shaft 6 is supported in the housing 51 by a ballbearing 55 which absorbs axial forces acting upon the drive shaft 6. Thesecond output shaft 8 is also rotatably supported in the housing 51 by aball bearing 58, the first output shaft 7 being rotatably supported bythe anti-friction bearing 38 in the hollow cylindrical part 36 and bytwo other anti-friction bearings 57A, 57B and an additional ball bearing56 in the second output shaft 8.

[0057] The drive unit 5 comprises in this embodiment the housing 51separately fastened on the housing 16 of the all-wheel distributortransmission 1. The arrangement of the drive unit 5 outside thetransmission housing 16 makes possible both a simple construction of thedrive unit 5 inasmuch as, for example, no cable seals have to beprovided in the housing, and an easy assembly.

[0058] However, in another embodiment of the all-wheel distributortransmission, it is left to the expert, depending on the existing case,to integrate the drive device 5 without its own housing in the housingof the all-wheel distributor transmission.

[0059]FIG. 4 shows an extensively schematized representation of thecontrol range of the drive device 5 and of the electromotor 9 where ahorizontal line with arrow points starting from a zero point “0”reproduces the two directions of rotation of the electromotor 9. On theoperating point reproduced with “0” the electromotor 9 is stationary.Starting from this point, there takes place a rotation over the angle αin direction of an operating point H (“high”) or an opposite directionover the angle −α in direction of a point L (“low”). The points L and Hsymbolize coupling points at which, in this case, takes place a shift ofthe electromagnetic clutch 30.

[0060] The area between the operating point “0” identifying a standstilland the coupling points L, H represents the control range of the firstoutput shaft 7. On the coupling points L, H a change over is made to acontrol of the second output shaft 8, the control range of whichattaches directly to the coupling points by the respective controlranges 59, 60 seen in FIG. 4.

[0061] In said control ranges 59, 60, the locking of the multi-disc lock4 is controlled, an active control of the multi-disc lock 4 occurring indirection “+α” and in direction “−α” acting the adjusting systemcomprised of set wheel 23, rolling bodies 61 and the adjusting element29. It is of particular advantage here that the control of the secondoutput shaft 8 begins without idling speed range immediately afterreaching the respective coupling points L and H.

[0062] In another embodiment it can also be provided that in the area ofthe ball-threaded pinion 12 a directional sensor be situated whichindicates when the coupling points L and H are reached so that anassociated electronic control unit can detect that it is possibleimmediately to start with the actuation of the second output shaft 8.

[0063] By uncoupling the drive of the multi-disc lock from the drive ofthe off-road gear actuation, there advantageously exists, in the shownembodiment of the all-wheel distributor transmission, one one-quadrantcontrol range which by control technology is easy to operate.

[0064] References  1 all-wheel distributor transmission  2multiplication step  3 second planetary gear set  4 lock or multi-disclock  5 drive device  6 drive shaft  7 first output shaft  8 secondoutput shaft  9 electromotor 10 shift unit 11 linear drive 12ball-threaded pinion 13 driver 14 ball 15 ball nut 16 housing of theall-wheel distributor transmission 17 synchronizer unit 18multiplication device 19 shaft 20, 21 gearwheel 22 spur wheel of secondoutput shaft 23 set wheel  23A recess 24 spline 25 inner discs 26front-wheel output shaft 27 outer discs 28 rear-wheel output shaft 29adjustment element  29A groove 30 electromagnetic clutch 31 couplingelement 32 point of rotation 34 flange-like collar 35 resilient element36 hollow cylindrical part 37 central hole 38 anti-friction bearing 39integral coil of the electromagnetic clutch 41 magnetic body of theelectromagnetic clutch 42 guide element 43 transmission element 44gearing of the transmission element 45 collar 46 electromagnetic brake47 integral coil of the electromagnetic brake 49 magnetic body of theelectric brake 50 brake element 51 housing 52 shaft flange of the driveshaft 53 resilient element 54 recess of drive shaft 55, 56 ball bearing57A, 57B anti-friction bearing 58 ball bearing 59, 50 control range 61rolling body, ball

1. All-wheel distributor transmission for a motor vehicle comprising aplanetary gear set as multiplication step for a switchable off-roadgear, a planetary gear set with variable division for distribution of adrive torque onto a front axle and a rear axle and a controllable lockto lock between the front axle and the rear axle, the lock and themultiplication step being actuatable via a controllable drive device,characterized in that said drive device (5) comprises one drive shaft(6) and two output shaft (7, 8), the first output shaft (7) beingoperatively connected with said multiplication step (2) and the secondoutput shaft (8) being operatively connected with said lock (4), and itbeing possible, depending on a control of a shift unit (10) forcontrolling said lock (4) or said multiplication step (2), to bring atorque fed via said drive shaft (6) to the first or the second outputshaft (7 or 8).
 2. All-wheel distributor transmission according to claim1, characterized in that said shift unit (10) has an electromagneticclutch (30) with which can be produced a power flow between said driveshaft (6) and said first or second output shaft (7 or 8).
 3. All-wheeldistributor transmission according to claim 1 or 2, characterized inthat said lock (4) and said multiplication step (2) can be driven bysaid drive device (5) sequentially translatorily and can be kept in oneposition.
 4. All-wheel distributor transmission according to any one ofclaims 1 to 3, characterized in that in the area of its end remote fromsaid drive shaft (6), said first output shaft (7) is in operativeconnection with a linear drive (11).
 5. All-wheel distributortransmission according to claim 4, characterized in that said lineardrive ( 11) comprises one ball-threaded pinion (12) and one tiltabledriver (13), said ball-threaded pinion (12) comprising a ball nut (15)in operative connection with said first output shaft (7) and havingseveral balls (14) and which, during a rotation of said first outputshaft (7), is adjusted in axial direction of said first output shaft (7)and produces a tiltable motion of said driver (13).
 6. All-wheeldistributor transmission according to claim 5, characterized in thatsaid driver (13) is tiltably supported in a housing (16) of saidall-wheel distributor transmission (1) and connected with a synchronizerunit (17) in a manner such that a tilting motion of said driver (13)produces an actuation of said multiplication step (2).
 7. All-wheeldistributor transmission according to any one of claims 1 to 6,characterized in that on its end remote from said output shaft (6), saidsecond output shaft (8) is connected with said lock (4) via amultiplication device (18).
 8. All-wheel distributor transmissionaccording to any one of claims 1 to 7, characterized in that said lock(4) has several axially movable discs (25, 27), the inner discs (25) ofsaid lock (4) being non-rotatably connected with a rear-wheel outputshaft (28) of said all-wheel distributor transmission (1) and outerdiscs (27) of said lock (4) being non-rotatably connected with afront-wheel output shaft (26) of said all-wheel distributor transmission(1).
 9. All-wheel distributor transmission according to claim 8,characterized in that to adjust said lock (4) there are provided one setwheel (23) and between said disc sets (25, 27) and said set wheel (23)one adjusting element (29) axially movable and non-rotatably situated insaid housing (16) of said all-wheel distributor transmission (1), saidadjusting element (29) having on its side facing said set wheel (23) atleast one groove (29A) for accommodating rolling bodies (61) whichcorresponds with at least one recess (23A) upon the side of said setwheel (23) facing said adjusting element (29) in a manner such as toproduce a rolling of said rolling bodies (61) and an axial motion ofsaid adjusting element (29).
 10. All-wheel distributor transmissionaccording to any one of claim 7 to 9, characterized in that saidmultiplication device (18) has two gear wheels (20, 21) fixedlyconnected with a shaft (19) and rotatably situated in said housing (16),said first gear wheel (20) being engaged with a spur gear (22) firmlyconnected with said second output shaft (8).
 11. All-wheel distributortransmission according to any one of claims 9 or 10, characterized inthat said lock (4), for producing the operative connection with saidsecond output shaft (8), is provided with a spline (24) extending atleast partly over the periphery of said set wheel (23).
 12. All-wheeldistributor transmission according to claim 10 or 11, characterized inthat said second gear wheel (21) of said shaft (19) is engaged with saidspline (24) of said set wheel (24).
 13. All-wheel distributortransmission according to any one of claims 2 to 12, characterized inthat said electromagnetic clutch (30) has an axially and rotatorilymovably guided coupling element (31) which is non-rotatably connectedwith said drive shaft (6) and depending on a current supply of saidelectromagnetic clutch (30) produces the power flow between said driveshaft (6) and said first or second output shaft (7 or 8).
 14. All-wheeldistributor transmission according to claim 13, characterized in thatsaid drive shaft (6) has in the area of its end facing said outputshafts (7, 8) a flange-like collar (34) on which is fastened a resilientelement (35) of said coupling element (31).
 15. All-wheel distributortransmission according to claim 13 or 14, characterized in that saidsecond output shaft (8) is designed as hollow shaft surrounding saidfirst output shaft (7) and on its end facing said drive shaft (6) can bebrought to operative connection with said coupling element (31) so thata non-rotatable connection exists between said drive shaft (6) and saidsecond output shaft (8) when said electromagnetic clutch (30) iscurrentless when the connection between said drive shaft (6) and saidfirst output shaft (7) is released.
 16. All-wheel distributortransmission according to any one of claims 13 to 15, characterized inthat said first output shaft (7) has in the area of its end facing saiddrive shaft (6) a collar (45) with which, in current-supplied state ofsaid electromagnetic clutch (30) contacts said coupling element (31) sothat a non-rotatable connection exists between said drive shaft (6) andsaid first output shaft (7), the connection between said drive shaft (6)and said second output shaft (8) then being released.
 17. All-wheeldistributor transmission according to claim 15 or 16, characterized inthat, to form the non-rotatable connection between said drive shaft (16)and said first or second output shaft (7 or 8), a form-locking orforce-locking connection is respectively provided.
 18. All-wheeldistributor transmission according to any one of claims 1 to 17,characterized in that, to unload said drive device (5), in the area ofsaid drive shaft (6) an electromagnetic brake (16) is provided withwhich said drive shaft (6) is non-rotatably retained in one positiondepending on a current supply of said electromagnetic brake (16). 19.All-wheel distributor transmission according to claim 18, characterizedin that said electromagnetic brake (46) comprises a brake element (5)non-rotatably with said drive shaft (6) and movable in axial directionof said drive shaft (6) which in current-supplied state of saidelectromagnetic brake (46) forms a power flow between said drive shaft(6) and said electromagnetic brake (46).